The present invention relates generally to case packing machines, and more particularly to case packing machines where containers or other articles are transferred from an infeed conveyor to a case loading station.
Case packing machines for packing bottles or other containers into compartmentalized and non-compartmentalized cartons are widely used. Typically, such case packing machines utilize a continuously-running infeed conveyor belt to advance the containers in side by side rows to a dead plate adjacent a loading station. From the dead plate, the containers are moved to the loading station. Once the containers are moved to the loading station, they are aligned in a grid structure, which commonly employs actuatable bars which support the containers immediately before being loaded into a case. Upon actuation of the bars, the containers are dropped as a group into the case positioned below the loading station.
Packing of the containers into the grid structure from the dead plate is usually done intermittently. Consequently, those containers positioned on the dead plate during the time between intermittent loadings of the grid structure experience line pressure exerted by upstream containers still being advanced by the continuously-running infeed conveyor belt. The line pressure, when exerted on the containers positioned on the dead plate, can result in undesirable distortion, jamming, or even breakage of containers, especially odd-shaped, flexible, or slender profiled containers, making difficult the correct loading of the grid structure with the containers. Such creates special problems in that, today, shapes of containers are consistently being changed from the traditional round shape to triangular, rectangular, square, or oblong shapes and the like. Further, because of the increased use of plastic containers, the problem with containers compressing and deforming under the influence of upstream conveyor line pressure is increased.
One particular problem arises with the packing of flask or oval-shaped containers. With these type of containers, there is a tendency for the narrow sides of adjacent containers to overlap each other or "shingle", causing the containers to become disordered. Because the containers to be packed are typically transported through walled lanes for maintaining the containers in rows, if the disordered configuration or "shingling" occurs, the containers may force outwardly on the walled lanes, causing the walls of the lanes to bulge such that containers transported in adjacent lanes are impeded to the point that they may no longer move. In such a situation, the lanes adjacent the dead plate area will become jammed such that the packing machine must be shut down in order for the situation to be alleviated.
Various case packing machines have been patented for transferring containers from an infeed conveyor to a case loading station. U.S. Pat. No. 3,273,723, granted to Andersen, discloses a packing machine having a bottle gripping head for gripping the upper portions of bottles on a conveyor and for transporting the bottles from the conveyor to a packing case. U.S. Pat. No. 3,327,450, granted to Carter, discloses a case packer having a pick-up head equipped with vacuum cups for transporting containers from a conveyor to a case packing station. U.S. Pat. No. 3,965,650, granted to Nussbaum, discloses a case packing machine having a removable drop plate assembly disposed beneath containers transported by a conveyor such that after the conveyors have advanced to a pre-packing staging position, the drop plate assembly is shifted for allowing the containers to fall into an underlying carton. And, U.S. Pat. No. 4,457,121, granted to Johnson et al., discloses a bottle packing machine having a rotating grid structure which receives containers from a conveyor and transfers them downwardly into a case.
Other types of container transport devices include inflatable gripping assemblies. One such assembly is disclosed in U.S. Pat. No. 2,784,997, granted to Baumann. Another such assembly is the Schaberger Pneumagrip manufactured by Pneumatic Scale Corporation of Quincy, Massachusetts. However, these devices are for depalletizing containers, not for transferring containers from an infeed conveyor to a case loading station.